The problems of foulant formation and/or foulant deposition have troubled downhole operations for years. Foulants accumulate on internal walls of various water systems, pipe surfaces, wellbore surfaces, etc. and thereby materially lessen the operational efficiency of a downhole operation.
Much of the foulant formation and/or foulant deposition occurs as a result of various components added to a fluid for various reasons, such as the salt for brine-based fluids, corrosion inhibition, bridging agents, scale inhibitors, and the like. The foulants may be or include scale, corrosion, and combinations thereof. The various corrosion forming components may cause corrosion to a downhole surface. The various scale forming components may precipitate from the fluid as scale, and it is this formed scale that may deposit onto a surface, which may occur at each instance of scale formation.
For example, corrosion may occur and/or scale may form because a brine-based fluid or system becomes saturated with a material due to a change in the flowing fluid conditions within the subterranean formation. Formation of corrosion and/or scale may occur when mixing insoluble waters, out-gassing, shear, turbulence, temperature and/or pressure changes, and combinations thereof; from pressure drops, water mixing points, outgassing points, shear points, gravel packs, and the like.
Chemical corrosion inhibitors decrease the amount and/or rate of corrosion formation and thereby decrease the amount of corrosion to a downhole surface. Chemical scale inhibitors decrease the amount and/or rate of scale formation in and around the surfaces within a subterranean formation, such as a subterranean reservoir wellbore.
Traditional inhibitors, such as ion exchange resins, polyacrylic acids, and the like are used as anti-foulants against scale and/or corrosion forming components. But such anti-foulants are extremely toxic, and other traditional inhibitors for decreasing corrosion and/or scale have not been satisfactory in an environment having a high amount of scale forming components, corrosion forming components, and/or a high amount of total dissolved solids.
For this reason, polyaspartic acid has been used for decreasing scale and/or corrosion on surfaces within a subterranean reservoir wellbore and/or surface in a refinery (e.g. an oil/gas refinery). However, polyaspartic acid is difficult to manufacture in large quantities. In addition, polyaspartic acid contains 50% alpha structures and 50% beta structures, but only the alpha structures are effective in decreasing formation and/or deposition of scale forming components and/or corrosion forming components onto a surface.
Thus, it would be desirable to determine other useful proteins for decreasing foulant formation and/or foulant deposition, but where the proteins are easily reproducible on a large scale.